Folding stool

ABSTRACT

A folding stool with legs and separate seat braces that extend from and are pivotally attached to a hub. When the stool is unfolded, the legs are retained in their normal, load supporting positions by angularly disposed edges on their minor portions,and the seat braces are also retained in their normal, load supporting positions. The legs can be folded to overlap the seat braces so that the stool can be folded the length of the legs or seat braces, whichever are longer.

United States Patent 11 1 UNITED STATES PATENTS Sprigman 1 1 Jan. 9,1973 541 FOLDING STOOL 550,256 11/1895 Deane ..24s/43s x I [75]Inventor: Arthur Sprigman, Queens Village, 323/38; 2413; 22:22:5 I NIY'V [73] Assignee: A. L. Doering Mfg. Corp., Bayside, PrimaryExaminer-JamesC. Mitchell -Y- Attorney-Brumbaugh, Graves, Donohue &Raymond 22 Pl F b. 25 1971 1 8 57 ABSTRACT [21] Appl. No.: 118,769

A folding stool with legs and separate seat braces that extend from andare pivotally attached to a hub. [52] US. Cl ..l08/l28, 248/435 w theStool is tw the legs are retained in [51] IIILCI. ..A47b 3/00 theirnormal, load supporting positions by angularly [58] Field of Search....l08/l28;248/l55.2, 155.3, disposed edges on their minor portionsandthe Seat 248/434 435 braces are also retained in their normal,- loadsupport- I ing positions. The legs canbefolded to overlap the [56]References Cited seat braces so that the stool can be folded the lengthof the legs or seat braces, whichever are longer.

I 8 Claims, 10 Drawing Figl rres PATENTEBJAN 9 I873 3,709,167

SHEET 1 [1F 3 I N V EN 70 R ARTHUR SPRIGMAN /&44 Pay/441) m onal l hisATTORNEYS.

PATENTEDJAH 9 197a SHEET 2 [IF 3 INVESTOR. ARTHUR SPRIGMAN hisATTORNEYS.

PATENTEU JAN 9 I973 SHEET 3 OF 3 ,MPMW

his ATTORNEYS FOLDING s'roor.

BACKGROUND OF THE INVENTION This invention relates to folding stools,and, in parpactly.

Conventional three-legged, folding stools normally have legs that arepivotally connected to each other near the center of each leg. A seatformed of a suitable flexible material is attached at or near the top ofeach leg. When stools constructed in this manner are folded, each leg ispivoted toward the common vertical axis of the legs resulting in thefolded length of the stool being no shorter than the combined length ofthe legs on both sides of their common pivot point. The net result is abulky and unwieldy folded stool. Since the object of such a stool is itsportability, the smaller the stool when folded, the closer the stoolapproaches serving its inherent purpose.

In addition, by providing a structure in which each leg extends fromboth sides of a common pivot point, the legs have a natural tendency tocome together when a person sits on the seat. This tendency is normallyresisted by the strength of each leg, which can result in a relativelylarge cross-sectional area for each leg or in the use of an expensive,high strength material. This reinforcement only adds to the bulkinessand weight of the structure and to its production cost.

Other folding stool structures have been designed, but these generallyutilize a complicated arrangement of frame and bracing members withoutany accompanying reduction in size when the stool is folded.

SUMMARY OF THE INVENTION Restraining structure to control pivotalmovement of the legs, in one embodiment of the invention, includes threeslugs within the hub capable of movement into and out of the path ofpivotal movement of the three legs. More specifically, each leg includesa major portion on one side of the pivot point and a minor-portion onthe other side, and the slugs may be moved into the paths of pivotalmovement of the minor portions of the legs. When that happens, the majorportions of the legs are prevented from moving outwardly and upwardlybeyond predetermined positions, thereby providing le'g supports for thestool in its unfolded, load supporting position. When the slugs aremoved out of the paths of pivotal movement of the minor portions of thelegs, the major portions are capable of moving upwardly beyond thehorizontal plane and parallel to the seat braces,

which also can be pivotally folded inwardly after their restrainingstructure is disabled. In this way, the stool There is provided, inaccordance with the invention, a stool that can be folded compactly. Theunique structure of the inventive stool enables it to be folded to thelength of its legs, which extend outwardly from a centrally located hub.The legs, in their normal folded position, overlap seat braces formed byseparate structural elements that also extend outwardly from the hub. In

this way a stool is provided which can be folded. to

about one-half of conventional folded stools.

A stool that is capable of being folded in this manner has manyadvantages over conventional stools. First, it is less bulky whenfolded. In addition, by providing a stool with legs and seat braces asseparate structural elements, stresses on those members are resisted bythe centrally located hub. This feature results in legs and seat bracesthat are subjected to smaller stresses than the stresses that must beresisted by single elements act.- ing as both legs and seat braces, asin conventional three-legged stools. Therefore, stools constructed inaccordance with the invention can be provided with structural elementsthat have a smaller cross-sectional area than the prior art stoolsdescribed above, when comparable materials are used.

The inventive stool includes a hub, with three legs and three separateseat braces pivotally attached to the hub and extending outwardly fromit. In their unfolded, load supporting positions, the legs extendgenerally downwardly and outwardly from the hub and are retained in thatposition by restraining structure, and the seat braces extend generallyupwardly and outwardly from the hub and are retained in position byadditional restraining structure. A seat-is attached at or near theouter extremities of theseatbraces.

can be folded to a length no longer than the length of the legs or thelength of the seat braces, whichever are longer.

In another embodiment of the invention, the restraining structure forthe legs includes an angular edge on each leg which is arranged toengage an associated surface on the hub. The seat brace restrainingstructure includes stops on the hub. With this arrangement, after usingthe stool, the legs may be folded inwardly and the seat braces pivoteddownwardly and folded to be coextensive with the legs.

DESCRIPTION OF DRAWINGS The above and other advantages of the inventionwill be more fully understood when the following descrip' tion isconsidered in conjunction with the accompanying drawings, in which: 7

FIG. 1 is a perspective view of the inventive folding stool in itsunfolded, load supportingposition;

FIG. 2 is a perspective viewof the folding stool when folded;

FIG. 3 is a partial front elevational view of the stool taken along line3--3 as shown in FIG. 1, with partial cut-away portions for clearerillustration of the component parts;

FIG. 4 is a partial top elevational view taken along line 4-4 as shownin FIG. 1, illustrating essentially the hub portion of the stool;

FIG. 5 is a partial top elevational view taken along line 5-5 as shownin FIG. 1, illustrating essentially the lock hub portion of the stool;

FIG. 6 is a partial cross-sectional view of the hub, taken along line6--6 as shown in FIG. 4, and illustrating essentially a groove and itscorresponding slugfor locking one of the legs;

FIG. 7 is a partial front elevational view taken along line 7-7 as shownin FIG. 2, illustrating the stool in its folded position with a portionof the hub being cut away forclear illustration of the groove and slug;

FIG. 8 is a partial front elevational view of another embodiment'of theinvention with partial cut-away portions for clarity;

FIG. 9 is a partial top elevational view taken along line 9-9 as'shownin FIG. 8, illustrating the hub portion of the modified stool; and

FIG. 10 is a partial front elevational view similar to FIG. 8showing'the stool in its folded position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to an embodiment ofthe invention with reference to FIG. 1, the folding stool is designatedgenerally by reference numeral and is shown in its normal unfolded, loadsupporting position. The main structural components that form the frameof the stool 10 are the hub 12, the legs 14 and seat braces 16 which arepivotally attached to the hub 12. When the stool 10 is unfolded, asshown in FIGS. 1 and 3, the legs 14 extend downwardly and outwardly andthe seat braces 16 extend upwardly and outwardly from the hub 12. Theseframe elements are preferably formed of a rigid, lightweight metal, butother rigid materials with relatively high strength characteristics mayalso be used. A seat 18, formed in this embodiment of a strong flexiblematerial, designated by the broken lines in FIG. 1, is .attached by anysuitable meanssuch as couplings 19 (best shown in FIG. 3), which arereadily removable to facilitate cleaning of the seat, at or near theouter extrernities of the seat braces 16.

The legs 14 and the seat braces 16 are attached to the hub 12 by pivotpins 20 which extend across channels 22 in the hub 12. A washer 24separates eachleg 14 and seat brace 16 to prevent them from rubbingagainst each other.

Each channel 22 is formed by a pair of integral parallel flanges thatare spaced apart-from each other and that extend outwardly from the sideof the hub 12.. Although the invention is described in conjunction withthe hub 12 having this particular design, other hubs may be used towhich the legs 14 and the seat braces 16 can be pivotally attached andwhich include restraining means for the legs 14, which operate in asimilar fashion to the type that will be described in greater detailbelow.

In this embodiment of the invention, as best shown in FIG. 4, each leg14 includes two portions, a major portion 26 that extends in onedirection from the pivot pin 20 and a minor portion 28 that extends inthe other direction from the pivot pin.

As best shown in FIGS. 3 and 4, a groove 30 runs longitudinally alongone side of the back wall of each channel 22. Part of the groove 30extends through the path of pivotal movement of the minor portion 28 ofthe leg 14. A slug 32, slidably disposed within each groove 30 (seeFIGS. 3, 6 and 7), is capable of moving into and out of the part ofgroove 30 that extends through the path of pivotal movement of the minorportion 28 of the leg 14. The slug 32 is preferably in the shape of arelatively flat rectangular body which has rounded longitudinal edges toconform to the shape of the groove 30 (see FIG. 4). Slugs and grooves ofother shapes may also be used.

To prevent the slug 32 from falling out of its groove 30, thelongitudinal opening of the groove 30 that opens into channel 22 isconstricted and, in addition,

pins 34 are received in holes 36 (see FIGS. 3, 4 and 7) I located in thehub 12 near both ends of the groove so that the head of each pin 34 atleast partially covers the groove 30, thereby acting as a stop for theslug 32. Instead of the pins 34, a single plate can be attached to eachend surface of the hub 12 to cover at least partially the ends of thegrooves 30. Other suitable stops may also be provided.

Each leg 14 includes a contact surface 38 (see FIG. 3) which is formedon an edge of the minor portion 28 of the leg 20 and is angularlydisposed to its longitu dinal axis. The angle of the contact surface 38deter-- mines the distance that the legs 14 can travel upwardly when thestool 10 is unfolded, as shown in FIGS. 1 and 3, which will be describedin greater detail below.

When the stool 10 is in its unfolded load supporting position as'shownin FIGS. 1 and 3, and a person is seated on the seat 18, each contactsurface 38 engages and is flush against its corresponding slug 32, andthe major portion 26 of that leg 14 cannot move outwardly in thedirection illustrated by the broken arrow 40 as shown in FIG. 3.

In addition, as a person is sitting on the seat 18 each seat brace 16tends to fold inwardly in the direction illustrated by the broken arrow42, as shown in FIG. 3. This tendency is resisted by brace member 44 andlock hub 46, with each brace member 44 being attached at I one end toone seat brace 16 by pivot pin 48 and at the other end to the lock hub46 by pivot pin 50 (see FIGS. 3 and 5). When the seat braces 16 are attheir point of maximum outward and downward movement (when the stool 10is unfolded) the brace members 44 are slightly above the horizontal.Because of the gap 52 (see FIG. 3) between the end of each brace member44 and the corresponding portion of the lock hub 46, the

lock hub 46 can be moved overcenter by a slight downward push to theposition shown in FIG. 3, thereby causing the end of each of the bracemembers 44 nearest the pivot pin 50 to be below the end nearest thepivot pin 48 in relation to the horizontal. In this way, the bracemembers 44 and the lock'hub 46 are locked into their supporting positionto resist the tendency of the seat braces 16 to move inwardly as isshown by the broken arrow 42.

In addition, each seat brace 16 includes an angularly disposed contactsurface 54 which, along with the point of maximum extension of the bracemembers 44 and the lock hub 46, limits the outward and downward movementof the seat brace 16 when the stool 10 is unfolded. Each contact surface54 abuts the back wall of its corresponding channel 22 when the seatbraces 16 are in their unfolded position.

When the stool 10 is folded, as shown in FIGS. 2 and 7, the legs 14 andthe seat braces 16 are folded up wardly, coextensive and parallel witheach other. With the stool 10 in that position, each slug 32 will belocated in the bottom of its groove 30 and in the path of pivotalmovement of the minor portion 28 of the corresponding leg 14. To unfoldthe stool 10, it is turned upside down causing each slug 32 to gravitateinto the part of its groove 30 which is not in the path of pivotalmovement of the minor portion 28 of the leg 14, as illustrated by thebroken arrow 56 shown in FIG. 3. Each leg 14 is then pivoted outwardlyin relation to the vertical axis of the stool 10 to a point beyond theangle at which each of the legs 14 extend when the stool 10 is in itsunfolded, load supporting position illustrated in FIG. 1.

The stool 10 is then turned back to the position shown in FIG. 2, butwith the legs 14 extending downwardly from the hub 12. This actioncauses the slugs 32 to slide, this time moving by gravity into the pathof movement of the minor portion 28 of each corresponding leg 14 asillustrated by the broken arrow 58 shown in FIG. 7. Each leg 14 is thenpivotally moved upwardly and outwardly in the direction illustrated bythe broken arrow 40, as shown in FIG. 3, until each contact surface 38engages its corresponding slug 32. Each leg 14 is then in its normalload supporting position.

Seat braces 16 are then pivotally moved outwardly and downwardly untilthe contact surfaces 54 on the ends of each seat brace 16 abut the backwall of their corresponding channels 22. At this point of maximumoutward and downward movement of each of the seat braces 16, the bracemembers 44 are slightly above the horizontal, as described above. Thelock hub 46 is then pushed downwardly a short distance to its overcenterposition and the folding stool is then in its normal load supportingposition.

To fold the stool 10 into the position shown in FIG. 2, the lock hub 46is grasped andpulled upwardly which causes seat braces 16 to be movedupwardly and inwardly a short distance. The seat braces are then pushedinwardly in the direction illustrated by broken arrow 42 in FIG. 3, tothe position shown in FIG. 2. Each leg 14 is then pivotally moveddownwardly and inwardly a short distance, illustrated by broken arrow 60shown in FIG. 3, to move the contact surface 38 of each leg 14 out ofengagement with the slugs 32. The entire stool 10 is then turned upsidedown causing each slug 32 to slide into the part of its groove 30 thatis not within the path of pivotal movement of the minor portion 28 ofthe corresponding leg 14, as illustrated by the broken arrow 56 in FIG.3. The legs 14 are then pivotally moved outwardly and downwardly, asillustrated by the broken arrow 40 in FIG. 3 (in relation to the upsidedown position of the stool 10), until they are coextensive with the seatbraces 16, as shown in FIG. 2. At this point, the stool 10 is in itsnormal folded position with both the legs 14 and seat braces 16 inparallel relation from one side of the hub 12, thereby providing afolded stool which is about one-half the folded length of conventionalstools.

Referring to another embodiment of the invention with reference to FIGS.8, 9 and 10, a folding stool designated generally by reference numeral60 includes a hub 61, three legs 62 and three seat braces 63. Threechannels 64 formed in the hub 61 by flanges 65 receive the ends of thelegs 62 and the braces 63 which are separated by spacers 66. Pivot pins67 extend through openings in the legs, braces and spacers to enable thelegs and braces to be pivotally moved in a limited manner as discussedhereinafter. A stop pin 68 affixed to the flanges 65 extends across eachchannel 64 to restrain movement of the seat braces 63.

On the inner end of each leg 62 there is formed an edge 69 angularlydisposed to the major longitudinal axis of the leg and engaging, whenthe stool is in use, a surface 70 parallel to the axis of the hub.

A triangular flexible seat 71 supported by the braces 63 is attached tothree couplings 72. One of the couplings is secured to one of the seatbraces 63 by a pin 73 inserted in an opening in the brace, and the othertwo couplings are adapted to be removably secured to the seat braces byslots 74 which receive the pins 73.

When the stool shown in FIGS. 8, 9 and 10 is folded, the legs and seatmembers extend coextensively from the hub, as shown in FIG. 10. Tounfold the stool for use, the seat braces 63 are pivoted upwardly intoengagement with the stop pins 68 to the position shown in FIG. 8 and thecouplings 72 of the seat are readily slipped into the slots 74 due tothe flexibility and resilience of the seat material. Note that the seattends to hold the braces in position. The legs are then pivotedoutwardly until their edges 69 engage the hub surfaces 70. The stool isthen ready for use.

To fold the stool 60, the seat 71 must first be removed from the twobraces and then the legs 62 and seat braces 63 pivoted downwardly intothe coextensive positions shown in FIG. 10. The resulting folded stoolis compact and readily transportable.

While the invention has been particularly described with regard to thepreferred embodiment, it is understood that the stool can assume othershapes and configurations and still be within the spirit and scope ofthe invention as described in the appended claims. Therefore, theinvention is not intended to be limited to the specific apparatusdisclosed herein but is to be defined by the appended claims.

I claim:

1. A folding stool capable of assuming folded and unfolded positionscomprising a hub, three legs pivoted to the hub for movement from foldedpositions to unfolded positions at which the legs normally extenddownwardly and outwardly from the hub, three seat braces pivoted to thehub for movement from folded positions coextensive with the folded legsto unfolded positions at which the braces normally extend upwardly andoutwardly from the hub, a seat adapted to be attached to the outer endsof the seat braces, first restraining means for preventing the seatbraces from pivotally moving inwardly from their unfolded positions whenthe stool is in use, and second restraining means for preventing thelegs from pivotally moving upwardly from their unfolded positions whenthe stool is in use, the three legs moving through paths to theirunfolded positions and the second restraining means including elementsmovably disposed on the hub and associated with each leg for preventingthe legs from pivotally moving upwardly from their unfolded positionswhen the movable elements are moved into the paths of pivotal movementof the legs and for allowing the legs to move pivotally upwardly andinto positions coextensive with the folded seat braces when therestraining means is moved out of the paths of pivotal movement of thelegs.

2. A folding stool capable of assuming folded and unfolded positionscomprising a hub, three legs pivoted to the hub for movement from foldedpositions to unfolded positions at which the legs normally extenddownwardly and outwardly from the hub, three seat braces pivoted to thehub for movement from folded positions coextensive with the folded legsto unfolded positions at which the braces normally extend upwardly andoutwardly from the hub, a seat adapted to be at-' tached to the outerends of the seat braces, first restraining means for preventing the seatbraces from pivotally moving inwardly from their unfolded posi tionswhen the stool is in use, and second restraining means for preventingthe legs from pivotally moving upwardly from their unfolded positionswhen the stool is in use, each leg including major and minor portionsextending in opposite directions from its pivot point, the majorportions extending downwardly and outwardly from the hub when the stoolis in its unfolded position, the minor portion moving through a pathwhen the leg is pivoted to its unfolded position, and the secondrestraining means including an edge of each leg minor portion, threegrooves in the hub, part of each groove extending through the path ofpivotal movement of one of the minor portion edges, a slug slidablydisposed in eachgroove, each slug being capable of movement into and outof the part of its groove that extends through the path of pivotalmovement of the minor portion edge so that when the stool is in itsnormal unfolded position the minor portion edges engage the slugs,thereby preventing the legs from pivotally moving upwardly beyond thepredetermined positions.

3. A folding stool in accordance with claim 2, wherein each slug ismovable due to gravity, and each groove includes stop means at each endthereof for preventing the slug from falling out of its groove.

4. A folding stool in accordance with claim 2, wherein the minor portionedge that engages the slug is an edge that is angularly disposed to themajor longitudinal axis of the leg, the angle determining the maximumdistance that the major portion of the leg can move upwardly when theedge engages the slug.

5. A folding stool in accordance with claim 2, wherein the hub includesthree channels formed by pairs of spaced apart flange members extendingoutwardly from the hub, and three pivot pins extending across thechannels and through the legs being anchored by the flanges forpivotally connecting the legs to the hub.

6. A foldingstool in accordance with claim 5, wherein each pivot pinalso extends through a seat brace, thereby pivotally connecting the legsand seat braces to the hub at the same pivot points.

7. A folding stool capable of assuming folded and unfolded positionscomprising a hub, three legs pivoted to the hub for movement from foldedpositions to unfolded positions at which the legs normally extenddownwardly and outwardly from the hub, three seat braces pivoted to thehub for movement from folded positions coextensive with the folded legsto unfolded positions at which the braces normally extend upwardly andoutwardly from the hub, a seat adapted to be attached to the outer endsof the seat braces, first restraining means for preventing the seatbraces from pivotally moving inwardly from their unfolded positions whenthe stool is in use, and secondrestraining means for preventing the legsfrom pivotally moving upwardly from their unfolded positions when thestool is in use, the first restraining means comprising a lock hub andthree brace members pivotally connected at their one ends to the seatbraces and at their other ends to the lock hub, the longitudinal axes ofthe brace members being slightly above the horizontal when the stool isin its normal unfolded position, and means providing overcenter actionof the lock hub when it is moved downwardly a short distance through thehorizontal position of the brace members for preventing the seat bracesfrom moving inwardly from their unfolded ositions when the stool is inuse.

8. A Folding stool capable of assuming folded and unfolded positionscomprising a hub that includes three pairs of spaced apart flangemembers extending outwardly from the hub, each pair of flange membersforming a channel between them, a pivot pin anchored by each pair offlange members and extending across the channel, a leg and a seat bracepivotally attached tothe hub by each pivot pin, each leg including majorand minor portions extending in opposite directions from its pivot pin,a seat attached to the ends of the seat braces, first restraining meansfor preventing the seat braces from pivotally moving inwardly from theirunfolded positions when the stool is in use, the hub further including agroove extending along a portion of the back wall of each channel, aportion of each groove extending through the path of pivotal movement ofthe minor portion of the leg, and a slug slidably disposed in

1. A folding stool capable of assuming folded and unfolded positionscomprising a hub, three legs pivoted to the hub for movement from foldedpositions to unfolded positions at which the legs normally extenddownwardly and outwardly from the hub, three seat braces pivoted to thehub for movement from folded positions coextensive with the folded legsto unfolded positions at which the braces normally extend upwardly andoutwardly from the hub, a seat adapted to be attached to the outer endsof the seat braces, first restraining means for preventing the seatbraces from pivotally moving inwardly from their unfolded positions whenthe stool is in use, and second restraining means for preventing thelegs from pivotally moving upwardly from their unfolded positions whenthe stool is in use, the three legs moving through paths to theirunfolded positions and the second restraining means including elementsmovably disposed on the hub and associated with each leg for preventingthe legs from pivotally moving upwardly from their unfolded positionswhen the movable elements are moved into the paths of pivotal movementof the legs and for allowing the legs to move pivotally upwardly andinto positions coextensive with the folded seat braces when tHerestraining means is moved out of the paths of pivotal movement of thelegs.
 2. A folding stool capable of assuming folded and unfoldedpositions comprising a hub, three legs pivoted to the hub for movementfrom folded positions to unfolded positions at which the legs normallyextend downwardly and outwardly from the hub, three seat braces pivotedto the hub for movement from folded positions coextensive with thefolded legs to unfolded positions at which the braces normally extendupwardly and outwardly from the hub, a seat adapted to be attached tothe outer ends of the seat braces, first restraining means forpreventing the seat braces from pivotally moving inwardly from theirunfolded positions when the stool is in use, and second restrainingmeans for preventing the legs from pivotally moving upwardly from theirunfolded positions when the stool is in use, each leg including majorand minor portions extending in opposite directions from its pivotpoint, the major portions extending downwardly and outwardly from thehub when the stool is in its unfolded position, the minor portion movingthrough a path when the leg is pivoted to its unfolded position, and thesecond restraining means including an edge of each leg minor portion,three grooves in the hub, part of each groove extending through the pathof pivotal movement of one of the minor portion edges, a slug slidablydisposed in each groove, each slug being capable of movement into andout of the part of its groove that extends through the path of pivotalmovement of the minor portion edge so that when the stool is in itsnormal unfolded position the minor portion edges engage the slugs,thereby preventing the legs from pivotally moving upwardly beyond thepredetermined positions.
 3. A folding stool in accordance with claim 2,wherein each slug is movable due to gravity, and each groove includesstop means at each end thereof for preventing the slug from falling outof its groove.
 4. A folding stool in accordance with claim 2, whereinthe minor portion edge that engages the slug is an edge that isangularly disposed to the major longitudinal axis of the leg, the angledetermining the maximum distance that the major portion of the leg canmove upwardly when the edge engages the slug.
 5. A folding stool inaccordance with claim 2, wherein the hub includes three channels formedby pairs of spaced apart flange members extending outwardly from thehub, and three pivot pins extending across the channels and through thelegs being anchored by the flanges for pivotally connecting the legs tothe hub.
 6. A folding stool in accordance with claim 5, wherein eachpivot pin also extends through a seat brace, thereby pivotallyconnecting the legs and seat braces to the hub at the same pivot points.7. A folding stool capable of assuming folded and unfolded positionscomprising a hub, three legs pivoted to the hub for movement from foldedpositions to unfolded positions at which the legs normally extenddownwardly and outwardly from the hub, three seat braces pivoted to thehub for movement from folded positions coextensive with the folded legsto unfolded positions at which the braces normally extend upwardly andoutwardly from the hub, a seat adapted to be attached to the outer endsof the seat braces, first restraining means for preventing the seatbraces from pivotally moving inwardly from their unfolded positions whenthe stool is in use, and second restraining means for preventing thelegs from pivotally moving upwardly from their unfolded positions whenthe stool is in use, the first restraining means comprising a lock huband three brace members pivotally connected at their one ends to theseat braces and at their other ends to the lock hub, the longitudinalaxes of the brace members being slightly above the horizontal when thestool is in its normal unfolded position, and means providing overcenteraction of the lock hub when it is moved downwardly a short distancethrough the horizontal position of the brace mEmbers for preventing theseat braces from moving inwardly from their unfolded positions when thestool is in use.
 8. A folding stool capable of assuming folded andunfolded positions comprising a hub that includes three pairs of spacedapart flange members extending outwardly from the hub, each pair offlange members forming a channel between them, a pivot pin anchored byeach pair of flange members and extending across the channel, a leg anda seat brace pivotally attached to the hub by each pivot pin, each legincluding major and minor portions extending in opposite directions fromits pivot pin, a seat attached to the ends of the seat braces, firstrestraining means for preventing the seat braces from pivotally movinginwardly from their unfolded positions when the stool is in use, the hubfurther including a groove extending along a portion of the back wall ofeach channel, a portion of each groove extending through the path ofpivotal movement of the minor portion of the leg, and a slug slidablydisposed in each groove, each slug being capable of sliding into and outof said portion of each groove, so that the major portions of the legsare prevented from pivotally moving upwardly from their unfoldedpositions when the slugs are in said portions of the grooves and thelegs engage the slugs, and the legs are permitted to move pivotallyupwardly to positions coextensive with the folded seat braces when theslugs are slidably moved out of said portions of the grooves.